Volume Rendering

Direct volume rendering (DVR) can be described as a visualization of a discrete volumetric datasetby mapping each value to a color and opacity. Each value in the dataset is referred to as a voxel,which is a general representation for a value on a regular grid in three dimensional space. Thetypically techniques used to render the dataset try to compute a discrete approximation of thevolume rendering integral.

Some additional general information about volume rendering can be found on this site.